NAME

XML::Parser::EasyTree - Easier tree style for XML::Parser

SYNOPSIS

  use XML::Parser;
  use XML::Parser::EasyTree;
  $XML::Parser::Easytree::Noempty=1;
  my $p=new XML::Parser(Style=>'EasyTree');
  my $tree=$p->parsefile('something.xml');

DESCRIPTION

XML::Parser::EasyTree adds a new "built-in" style called "EasyTree" to XML::Parser. Like XML::Parser's "Tree" style, setting this style causes the parser to build a lightweight tree structure representing the XML document. This structure is, at least in this author's opinion, easier to work with than the one created by the built-in style.

When the parser is invoked with the EasyTree style, it returns a reference to an array of tree nodes, each of which is a hash reference. All nodes have a 'type' key whose value is the type of the node: 'e' for element nodes, 't' for text nodes, and 'p' for processing instruction nodes. All nodes also have a 'content' key whose value is a reference to an array holding the element's child nodes for element nodes, the string value for text nodes, and the data value for processing instruction nodes. Element nodes also have an 'attrib' key whose value is a reference to a hash of attribute names and values. Processing instructions also have a 'target' key whose value is the PI's target.

EasyTree nodes are ordinary Perl hashes and are not objects. Contiguous runs of text are always returned in a single node.

The reason the parser returns an array reference rather than the root element's node is that an XML document can legally contain processing instructions outside the root element (the xml-stylesheet PI is commonly used this way).

If the parser's Namespaces option is set, element and attribute names will be prefixed with their (possibly empty) namespace URI enclosed in curly brackets.

SPECIAL VARIABLES

Two package global variables control special behaviors:

XML::Parser::EasyTree::Latin: If this is set to a nonzero value, all text, names, and values will be returned in ISO-8859-1 (Latin-1) encoding rather than UTF-8.
XML::Parser::EasyTree::Noempty: If this is set to a nonzero value, text nodes containing nothing but whitespace (such as those generated by line breaks and indentation between tags) will be omitted from the parse tree.

EXAMPLE

Parse a prettyprined version of the XML shown in the example for the built-in "Tree" style:

  #!perl -w
  use strict;
  use XML::Parser;
  use XML::Parser::EasyTree;
  use Data::Dumper;
  
  $XML::Parser::EasyTree::Noempty=1;
  my $xml=<<'EOF';
  <foo>
    <head id="a">Hello <em>there</em>
    </head>
    <bar>Howdy<ref/>
    </bar>
    do
  </foo>
  EOF
  my $p=new XML::Parser(Style=>'EasyTree');
  my $tree=$p->parse($xml);
  print Dumper($tree);

Returns:

  $VAR1 = [
          { 'name' => 'foo',
            'type' => 'e',
            'content' => [
                           { 'name' => 'head',
                             'type' => 'e',
                             'content' => [
                                            { 'type' => 't',
                                              'content' => 'Hello '
                                            },
                                            { 'name' => 'em',
                                              'type' => 'e',
                                              'content' => [
                                                             { 'type' => 't',
                                                               'content' => 'there'
                                                             }
                                                           ],
                                              'attrib' => {}
                                            }
                                          ],
                             'attrib' => { 'id' => 'a'
                                         }
                           },
                           { 'name' => 'bar',
                             'type' => 'e',
                             'content' => [
                                            { 'type' => 't',
                                              'content' => 'Howdy'
                                            },
                                            { 'name' => 'ref',
                                              'type' => 'e',
                                              'content' => [],
                                              'attrib' => {}
                                            }
                                          ],
                             'attrib' => {}
                           },
                           { 'type' => 't',
                             'content' => '
  do
 '
                           }
                         ],
            'attrib' => {}
          }
        ];

AUTHOR